EP4015708B1 - Concrete block for producing a surface covering, surface covering and method for manufacturing a concrete block - Google Patents

Description

Technical area

The invention relates to a concrete block for creating a surface covering, to a surface covering which is produced by concrete blocks laid in a composite, and to a method for producing a concrete block.

State of the art

Concrete blocks for creating surface coverings are well known from the prior art. Such concrete blocks, which are usually so-called shaped blocks made of concrete, are to be understood as surface covering elements made of concrete, which, depending on the type of application, can be shaped like a plate or stone and are usually also referred to as concrete paving stones. The production of the concrete blocks is usually done with the help of formwork molds and is carried out, for example, by machine.

Surface coverings of the type mentioned are produced by laying the concrete blocks, in particular by laying them in a composite manner, and are also commonly referred to as paving or paving. Such surface coverings are used in both private and public spaces and are used, for example, to design squares and streets in urban areas. Likewise, in private spaces, terraces, property entrances or driveways or forecourts are designed with such surface coverings.

The surface coverings mentioned are often used on areas where the surface coverings are not only walked on by pedestrians, but also driven on by vehicles, for example on traffic areas for heavy goods traffic. Therefore, these surface coverings are often subject to strong dynamic, mechanical stress, for example due to the acceleration and braking of cars, trucks or other heavy-duty vehicles.

The mechanical load mentioned and the resulting dynamic forces can lead to the structure of the usually laid in a composite Surface coverings are affected. For example, due to the forces that occur, individual concrete blocks can move relative to the neighboring concrete blocks of the structure; in particular, concrete blocks or concrete slabs can also loosen in a relatively short time. Examples of shaped stones or paving stones made of concrete that are laid in a composite are from DE 10 2016 116 443 A1 or from the EP 3 153 625 A1 known. The dynamic forces that occur due to the mechanical loads can therefore affect individual concrete blocks or groups of concrete blocks and, for example, lead to displacements. This not only makes the appearance of the surface covering unsightly, but it can ultimately lead to damage to the surface covering or the traffic area, which increasingly spreads as the loosened surfaces continue to be driven on.

In order to counteract these dynamic forces or to absorb and remove them, so-called displacement locks are already used in the prior art, which can be designed differently. Known anti-displacement devices have in common that they are used when laying the concrete blocks or concrete slabs in such a way that they rest on the concrete blocks or concrete slabs and ensure that they are supported or anchored in the subsoil or the bedding or the base layer at least in a predetermined direction of displacement.

For example, plate-shaped displacement locks are made from the DE 20 2013 005 763 U1 or the DE20 2017 005 452 U1 known, which has a preferably flat base plate made of metal with several threaded holes. Threaded pins can be inserted into the threaded holes, which create so-called spikes to anchor the base plate in the subsurface. The threaded pins can also extend from the underside of the base plate through the threaded hole beyond the top of the base plate and protrude upwards from it. This creates contact surfaces or contact webs for the side surfaces of the concrete blocks or concrete slabs, which prevent them from shifting in at least one direction of displacement. However, the disadvantage here is that such plate-shaped anti-displacement devices need to be installed underneath the surface covering, in particular before the concrete blocks or concrete slabs are laid.

Concrete blocks are also known from the prior art, which are shaped or shaped in such a way that the concrete blocks themselves provide protection against displacement.

The DE 10 2005 049 555 A1 discloses, for example, a concrete block in which projections are formed in the area of the underside, which are arranged regularly in rows, whereby the concrete block is secured against displacement. However, this anti-displacement protection only has a disadvantageous effect at certain points and only against displacement in the transverse and longitudinal directions, which means that possible displacements in further lateral directions cannot be counteracted.

From the DE 10 2006 022 644 A1 It is also known to treat a concrete block in the area of the underside with a setting retarder during its production and then to wash out concrete in the treated areas of the underside. As a result, the coarser or larger aggregate material contained in the concrete is partially exposed, with the exposed aggregate forming an anti-shift mechanism. The disadvantage here, however, is that the displacement protection is only very superficial. Due to the post-processing steps required to create the anti-displacement device, its dimensions or design are heterogeneous and can only be created in the same defined manner with difficulty in a controllable manner. Equally disadvantageous is the production of the concrete block, which is time-consuming and labor-intensive due to the various post-treatment steps. Furthermore, from the DE 102 18 634 an artificial stone is known that has a lower layer of cement-bound broken natural stones. The publication JP 2003 293 303 A discloses a surface covering element in which a coarse concrete surface is provided on the underside.

The known concrete blocks with anti-displacement devices are therefore not, or only to a very limited extent, suitable for surface coverings that can withstand high mechanical loads and can be laid, for example, on traffic areas for heavy goods traffic. Therefore, there is still a need for improved concrete blocks.

Presentation of the invention

The object of the present invention is therefore to provide a concrete block which overcomes the disadvantages of the prior art and which, even under the influence of heavy loads, provides particularly effective protection against displacement and can be produced inexpensively, easily and reproducibly. According to the invention, this task is achieved independently by the concrete block Claim 1 solved. Furthermore, to solve the problem, a surface covering according to claim 8 and a method for producing a concrete block according to claim 12 are specified. Further advantageous aspects, details and refinements of the invention result from the dependent claims, the description and the drawings.

The present invention provides a concrete block, in particular in the form of a paving stone that can be laid in a composite, for creating a surface covering. The present concrete block has at least one multi-layered concrete block body with at least one concrete block underside suitable for laying on a bedding layer of a substrate and a concrete block upper side opposite this. The multilayer concrete block body comprises at least one first concrete block layer made from a core concrete material and designed as a core concrete layer and at least one second concrete block layer arranged on the underside of the concrete block and further at least one third concrete block layer formed as a facing concrete layer and arranged on the top of the concrete block. The concrete block is characterized in particular by the fact that the second concrete block layer is a coarse, heap-porous concrete layer which is made from concrete with a coarse aggregate. The second concrete block layer is designed as an interlocking layer for interlocking with the bedding layer of the subsoil. Due to the second layer of concrete blocks, the underside of the concrete block is equipped with a coarse-grain surface that provides a large number of toothing elements.

It is particularly advantageous for the concrete block to have means for interlocking with the bedding layer through the second layer of concrete block arranged on the underside as an interlocking layer, namely through the coarse, porous concrete layer. Due to the coarse aggregate in the concrete of the coarse, porous concrete layer, the coarse-grained surface on the underside of the concrete block has both depressions and projections relative to a lower concrete block boundary plane. These depressions and projections serve as interlocking structures or as interlocking means for interlocking with the bedding layer on which the concrete blocks are laid to create a surface covering and on which the underside of the concrete blocks rest when laid.

The second concrete block layer, which is designed as a coarse, porous concrete layer, can also be understood as a pore layer, which has an approximately porous, porous, perforated structure, but has sufficient strength and stability to withstand high mechanical forces and heavy loads, for example from heavy traffic. In particular, the coarse, porous concrete layer has a precisely defined layer thickness.

For the purposes of the invention, “rock grain” is to be understood as meaning a granular material, in particular natural and artificial rock grains. The rock grains can be present either as round grains or in broken form. The aggregate is together with water and cement for the Suitable for the production of concrete and is used for this purpose. For example, aggregates can be divided into so-called grain groups or grain sizes. For the purposes of the present invention, the grain size indicates a rock grain diameter of the rock grains or a range of a rock grain diameter. The aggregate can be understood as a mixture of aggregates, whereby the aggregates present in the mixture can have different diameters, but the diameters lie within a predetermined or limited range, preferably within a narrowly limited range. The rock grains present in the aggregate thus have a predetermined grain size distribution, preferably in a narrow range, with the grain size in the present case also being understood as a value for the average aggregate diameter of an aggregate.

According to the present understanding, the coarse aggregate is preferably a broken aggregate, with the aggregate preferably having edges and fracture surfaces. The coarse aggregate can also be referred to as grit in this case and can be clearly distinguished from a fine aggregate, which, in contrast to the coarse aggregate, is to be understood as sand or crushed sand. The coarse aggregate in the sense of the present invention has a grain size with a value that is larger than the value of 0 to 4 mm usually specified in the technical field for fine aggregate. In the present understanding, fine particles with grain sizes below 4 mm are essentially excluded from the coarse aggregate and are not present or only present in traces in the coarse aggregate.

The coarse-grained surface on the underside of the concrete block caused by the second concrete block layer of the present concrete block can also be referred to as a rough surface or textured surface or as an irregularly structured, relief-like uneven surface. The projections in the coarse-grained surface are formed in particular by respective grains or rock grains of the coarse rock grain that protrude outwards beyond the concrete block boundary plane. The depressions in turn are formed by the unfilled spaces or cavities or pores present between the rock grains in the aggregate-porous concrete of the second concrete block layer. These spaces or cavities face the outside in the area of the lower concrete block boundary level open and protrude - starting from the outer surface - as an unfilled space or as a cavity into the second concrete block layer.

For interlocking between the concrete block and the bedding layer, the projections of the coarse-grained surface advantageously engage in the bedding material and at the same time bedding material is accommodated in the depressions of the coarse-grained surface. This particularly advantageously results in effective interlocking, which secures the concrete block against shifting and slipping relative to the subsurface. A particularly effective interlocking and a particularly reliable protection against displacement is guaranteed if the coarse aggregate of the concrete of the second concrete block layer is an aggregate of sharp-edged quarry stones, namely chippings. The second concrete layer designed to interlock with the bedding layer thus represents an integral anti-displacement protection or an integral anti-displacement protection of the concrete block. The present concrete block can therefore also be understood as a concrete block with anti-displacement protection or as a concrete block with anti-displacement protection.

Particularly advantageously, due to the second concrete block layer formed in the form of the coarse, aggregate-porous concrete layer, the toothing means are arranged distributed over the entire surface of the entire underside of the concrete block, so that a flat, in particular full-surface or area-covering, toothing is made possible. The irregular arrangement of the toothing means over the surface of the underside of the concrete block advantageously results in anti-displacement protection or anti-displacement protection in a large number of possible displacement directions. The concrete block is therefore secured against lateral displacement movements in a variety of directions.

According to a preferred embodiment variant of the invention, the coarse aggregate of the concrete of the second concrete block layer has a grain size in a range of approximately 5 mm to 15 mm. Particularly preferably, the coarse aggregate of the concrete of the second concrete block layer has a grain size in a range of approximately 5 mm to 8 mm or in a range of 8 mm to 11 mm.

The second concrete block layer is particularly preferably made from a sand-free and/or fine aggregate-free concrete. In the present case, this means that no sand or fine aggregate is mixed into the concrete, so that the concrete advantageously does not contain any fine particles to be measured apart from the cement content. This ensures that the spaces or pores between the rock grains Fine aggregates should not be added to the coarse aggregate. It is understood that traces of sand or fine aggregate present in the concrete, which are introduced via the coarse aggregate, are negligible and are not considered mixed sand or fine aggregate in the present understanding.

According to an advantageous embodiment of the invention, the second concrete block layer has a layer thickness which is approximately 10% to 50% of the height of the concrete block, in particular around 20% of the height of the concrete block. The layer thickness of the second concrete block layer can be determined and variably selected in a defined manner depending on the desired application of the concrete block, as well as on the specific geometric shape of the concrete block and depending on the coarse aggregate used. The layer thickness is preferably at least as large as the average grain size of the aggregate used. For example, the layer thickness of the second concrete block layer when using an aggregate with a grain size in a range of 8 mm to 11 mm is approximately around 1 cm. In any case, the layer thickness is chosen to be sufficiently large to ensure that the second concrete block layer is permanently and firmly as well as stable and securely connected to the first concrete block layer or remains connected to it, even under high mechanical loads and under the influence of given environmental influences.

In the present case, the “second concrete block layer” can also be understood to mean that it is not to be viewed as a completely self-supporting layer. Protruding aggregates, which are integrated into the overall grain structure through partial "embedding" or due to partial penetration or protrusion into the first concrete block layer and are therefore firmly anchored in the concrete block, can form the second concrete block layer. The layer thickness of a second concrete block layer designed in this way can therefore, depending on the application, also be smaller than the average grain size of the aggregate used.

The surface of the underside of the concrete block is preferably open-pored and comprises a plurality of pores that are open to the outside, the pores that are open to the outside having a respective pore opening. At least some of the outwardly open pores on the surface of the underside of the concrete block have a pore opening with an opening width in a range of 1 mm to 8 mm, in particular in a range of 2 to 5 mm, and a pore depth in a range of around 1 mm up to 8 mm, in particular in a range of around 2 to 5 mm.

According to the invention, the concrete block body further has at least one third concrete block layer designed as a facing concrete layer, which is arranged on the top of the concrete block. Very particularly preferably, the third concrete block layer is made from a structurally dense facing concrete, in particular from a structurally dense facing concrete with fine aggregates and/or aggregates for the optical design of the top of the concrete block. Preferably, the concrete block body can have further layers, which can be arranged between the third and first or between the first and second layers. For example, layers can be provided to regulate the absorption and/or release of rainwater or layers to filter rainwater.

The concrete block has at least three adjacent peripheral sides, the peripheral sides having a coarse-grained side surface section at least partially in the area of the second concrete block layer. In analogy to the coarse-grained surface on the underside of the concrete block, the coarse-grained side surface sections are also designed and suitable for interlocking with the bedding material of the bedding layer and/or for interlocking with a joint material which is used to fill joints in the surface covering. Due to the coarse-grained side surface sections, the displacement protection or the displacement protection can be additionally supported and improved and displacement can be prevented particularly effectively.

The concrete block preferably has one or more laterally arranged spacers or spacer lugs, which are preferably arranged on at least one of the peripheral sides at least in the area of the first concrete block layer and are designed, for example, in the form of projections formed on the concrete block body. Such spacers or spacer lugs can advantageously be used to ensure that when creating a surface covering by laying several concrete blocks between the respective concrete blocks, uniform joints, in particular joints of uniform width, are formed and a minimum joint width is maintained.

The present invention also relates to a surface covering comprising a large number of concrete blocks laid in a composite manner by paving, as described above, and at least one bedding layer arranged on a subsurface. Each concrete block has a multi-layered concrete block body with at least one underside of the concrete block and one opposite it Concrete block top, wherein the multilayer concrete block body comprises at least one first concrete block layer designed as a core concrete layer and at least one second concrete block layer arranged on the underside of the concrete block. The surface covering is characterized in particular by the fact that the second concrete block layer of the concrete blocks is a coarse, porous concrete layer and is made from concrete with a coarse aggregate. Due to the second concrete block layer designed as an interlocking layer for interlocking with the bedding layer of the subsoil, the concrete blocks have a coarse-grained surface on their underside of the concrete block and are interlocked with the bedding layer via their respective second concrete block layer and are thereby secured against displacement.

The bedding layer preferably has a bedding material in the form of a chippings material, the chippings material of the bedding layer interacting with the coarse-grained surface for interlocking with the second concrete block layer and/or at least partially engaging in pores of the second concrete block layer that are open to the outside.

Joints are preferably formed between respective adjacent concrete blocks of the surface covering, the joints being filled with a chippings and/or sand-like joint material. Very particularly preferably, the concrete blocks each have a coarse-grained side surface section on their peripheral sides in the area of the second concrete block layer, at least in sections, the coarse-grained side surface sections of the concrete blocks interacting with the joint material in an interlocking manner.

The present invention also provides a method for producing the concrete block described above. In the method, after providing a suitable formwork form for producing a first concrete block layer designed as a core concrete layer, a core concrete material is filled into the formwork form and preferably compacted. In a further step, a second concrete block layer is produced, which defines a concrete block underside of the concrete block produced. The method is characterized in particular by the fact that the second concrete block layer is produced as a coarse, porous concrete layer and the concrete block is thereby provided with a coarse-grained surface on its underside. For this purpose, concrete with a coarse aggregate is provided and on top of the core concrete material that has already been introduced into the formwork and is preferably compacted refilled. Finally, the process hardens the core concrete material and the concrete with coarse aggregate.

Before refilling the concrete provided for the production of the second concrete block layer, an adhesion promoter can preferably be applied to the core concrete of the first concrete block layer located in the mold in order to improve or stabilize the connection of the first and second concrete block layers. To produce the second concrete block layer, a concrete is preferably used which has a coarse aggregate with a grain size in a range of approximately 5 mm to 15 mm, in particular with a grain size in a range of approximately 5 mm to 8 mm or in a range of 8 mm up to 11 mm. Particular preference is given to using a concrete that is free of sand and/or fine aggregates to produce the second concrete block layer.

According to a particularly advantageous embodiment variant, to produce the second concrete block layer, a sufficient amount of concrete is filled in to produce the second concrete block layer with a layer thickness that is between approximately 10% and 50% of a height of the concrete block, in particular around 20% of the height of the concrete block

According to the invention, as an additional step before filling the core concrete material into the formwork mold, a facing concrete material is first filled into the formwork mold and compacted to produce a third concrete block layer designed as a facing concrete layer.

Brief description of the drawings

Fig. 1

beispielhaft in grob vereinfachter Darstellung eine perspektivische Ansicht eines nicht erfindungsgemäßen Betonsteins;

Fig. 2

den Betonstein der Figur 1 in einem schematischen Schnitt mit Schnittrichtung entlang einer vertikalen Achse und in einer Schnittebene parallel zu einer Hauptachse des Betonsteins;

Fig. 3

beispielhaft in grob vereinfachter Darstellung eine perspektivische Ansicht eines Ausführungsbeispiels eines erfindungsgemäßen Betonsteins;

Fig. 4

den Betonstein der Figur 3 in einem schematischen Schnitt mit Schnittrichtung entlang einer vertikalen Achse und in einer Schnittebene parallel zu einer Hauptachse des Betonsteins;

Fig. 5

sehr stark vereinfacht in Draufsicht auf die grobkörnige Oberfläche einen Ausschnitt der Betonsteinunterseite (Abschnitt A) mit resultierender Verschiebesicherung in diverse Richtungen (Abschnitt B) und

Fig. 6

beispielhaft einen aus mehreren Betonsteinen erstellten Flächenbelag in einem vertikalen Schnitt.

The invention will be explained in more detail below using exemplary embodiments in connection with the drawings. Show it

Fig. 1

By way of example, in a roughly simplified representation, a perspective view of a concrete block not according to the invention;

Fig. 2

the concrete block Figure 1 in a schematic section with a cutting direction along a vertical axis and in a cutting plane parallel to a main axis of the concrete block;

Fig. 3

By way of example, in a roughly simplified representation, a perspective view of an exemplary embodiment of a concrete block according to the invention;

Fig. 4

the concrete block Figure 3 in a schematic section with a cutting direction along a vertical axis and in a cutting plane parallel to a main axis of the concrete block;

Fig. 5

very simplified, a top view of the coarse-grained surface of a section of the underside of the concrete block (section A) with the resulting protection against displacement in various directions (section B) and

Fig. 6

For example, a surface covering made from several concrete blocks in a vertical section.

Ways of carrying out the invention

The concrete block, generally designated 1 in the figures, is preferably in the form of a surface covering element that can be laid in a composite to create a surface covering 10 (see Figure 6 ) formed, preferably in the form of a surface covering element that can be laid by paving. In particular, the concrete block 1 is therefore to be understood in the present case as a paving stone, which can also be designed in the form of a plate as a concrete slab, with a concrete block or a concrete slab being understood to mean essentially identical elements that can be used to create a surface covering 10 in a manner known per se. Depending on the chosen laying pattern, several of these concrete blocks 1 are connected to one another and flush with each other on the joint 13 (see e.g Figure 6 ) laid so that a preferably flat surface covering 10 with joints 13 is created. The concrete blocks 1 are suitable for the creation of surface coverings 10 on walkable or drivable traffic areas, such as large public squares, parking lots, streets, paths but also for use in private use to create courtyard, garden and/or terrace coverings. In particular, the concrete blocks 1 are also suitable for use in creating surface coverings 10 on traffic areas with heavy goods traffic.

In Figure 1 A perspective view of a concrete block 1 not according to the invention is shown as an example in a roughly simplified representation, with the concrete block 1 in Figure 2 is further shown in a schematic section, namely as a vertical section in a section plane parallel to a main axis HA and to a vertical axis VA of the concrete block 1.

The concrete block 1 has a multi-layer concrete block body 2 with a layer for laying on a bedding layer 3 (in Figures 1 and 2 not shown, see Figure 6 ) a concrete block underside 2.1 suitable for the substrate and an opposite concrete block top 2.2. In the present exemplary embodiment, the concrete block 1 is cuboid-shaped, with the opposite and essentially parallel concrete block undersides and concrete block upper sides 2.1, 2.2 having approximately the same area and with the vertical axis VA intersecting both the concrete block underside 2.1 and the concrete block upper side 2.2 vertically in the middle. The exemplary concrete block 1 has four circumferential sides 7, 7', 7", 7", each adjoining one another at right angles, which run essentially perpendicular to the lower and upper sides of the concrete block 2.1, 2.2.

However, the geometric design and dimensioning of the concrete block 1 are not relevant; in particular, the specific cross-sectional shape of the concrete block 1 and/or the dimensioning of the concrete block 1 can be chosen almost arbitrarily.

In the example of Figures 1 and 2 The multi-layer concrete block body 2 comprises two successive layers along the vertical axis VA, namely a first concrete block layer 4 designed as a core concrete layer, which is arranged at the top in the state of use and forms the concrete block top 2.2. In the exemplary embodiment, the first concrete block layer 4 thus also represents the surface that can be walked on or driven over, namely the visible surface or the exposed concrete of a concrete block 1 laid in the surface covering 10.

The first concrete block layer 4 is made from a core concrete material familiar to those skilled in the art, as is usually used for the production of paving stones, in order to give the concrete block 1 the required strength and durability as well as sufficient freeze-thaw resistance. In the present case, the core concrete material in particular is chosen so that it gives the concrete block 1 the strength and stability necessary for heavy goods traffic. The core concrete material used to produce the first concrete block layer 4, namely the core concrete, preferably contains a grain mixture, in particular in the form of a mixture of coarse and fine aggregate with grain sizes that vary within a wide range. For example, the core concrete material can also contain high-strength aggregates, such as quartz, granite, hard limestone or the like, which are added to the core concrete, for example as fine aggregates or fine aggregates. The core concrete for producing the first concrete block layer 4 is preferably a structurally dense concrete.

On the underside 2.1 of the concrete block 1, a second concrete block layer 5 is arranged, which forms an underside surface of the concrete block 1, namely a support surface, over which the concrete block 1 in the laid state on the bedding layer 3 (see. Fig. 6 ) of the subsurface.

The second concrete block layer 5 is a coarse, porous concrete layer which is made from a concrete with a coarse aggregate, the concrete for producing the second concrete block layer 5 being in particular free of fine aggregate, namely free of sand and/or fine aggregate or at most contains traces of it. The coarse, porous concrete layer is designed in such a way that the second concrete block layer 5 is designed as an interlocking layer for interlocking with the bedding layer 3 of the subsoil. The concrete block 1 is equipped with a coarse-grained surface 5a on the underside of the concrete block 2.1 via the coarse, porous concrete layer, which has a sufficient degree of coarse-grainedness or surface roughness for effective interlocking with the bedding layer 3. The surface quality, in particular coarse grain or surface roughness of the coarse-grain surface 5a, results from the coarseness and aggregate porosity of the second concrete block layer 5, which in turn is determined by the coarse aggregate contained therein.

On the coarse-grained surface 5a, relative to an imaginary, horizontally extending lower concrete block boundary plane E, both projections 11 and depressions 12 are present, as shown in the enlarged section A of the Figure 1 is visible. The projections 11 are formed from individual rock grains of the coarse aggregate in the concrete and protrude downwards beyond the lower concrete block boundary plane E. The depressions 12 are through the unfilled cavities or pores contained in the coarse, porous concrete formed between the rock grains of the coarse aggregate and extend from the lower concrete block boundary plane E into the second concrete layer 5. Both the projections 11 and the depressions 12 form toothing means for interlocking with the bedding layer 3.

Due to the second concrete block layer 5, the concrete block 1 also has a respective coarse-grained side surface section 7a on the peripheral sides 7, 7 ', 7", 7" of the concrete block body 2 in sections, namely in the area of the second concrete block layer 5, which is analogous to the coarse-grained Surface 5a on the underside of the concrete block 2.1 has projections and depressions which serve for interlocking with the material of the bedding layer 3 and / or for interlocking with a joint material used to fill the joints 13. The nature of the coarse-grained surface 5a is described below with reference to Figure 5 described in more detail.

In the example shown, the second concrete block layer 5 is made of a concrete that has a coarse aggregate in the form of an aggregate of sharp-edged quarry stones with a grain size of 8 mm to 11 mm. Such aggregate is also referred to as aggregate 8/11 and is to be understood as grit, in particular as grit with a grain size of 8-11 mm.

The second concrete block layer 5 of the exemplary concrete block 1 has a layer thickness d2 which is approximately a quarter of the height h of the concrete block 1. For the two-layer concrete block 1 Figures 1 and 2 The result is that a layer thickness d1 of the first concrete block layer 4 makes up around three quarters of the height h of the concrete block 1 and thus corresponds to approximately three times the layer thickness d2 of the second concrete block layer 5. It is understood that the layer thickness d2 of the second concrete block layer 5 can be designed to be variable depending on the application, depending on the desired use and the area of application of the concrete block 1, in particular in a different relation to the layer thickness d1 of the first concrete block layer 4. With regard to the absolute value of the layer thickness d2, however, depending on the coarse aggregate contained in the concrete for producing the second concrete block layer 5, there is a minimum layer thickness which approximately corresponds to the value of the average grain size of the coarse aggregate. The layer thickness d2 of the second concrete block layer 5 is preferably measured as the average layer thickness starting from the transition of the first 4 to the second concrete block layer 5 up to the concrete block boundary plane E or as the maximum layer thickness starting from the transition of the first 4 to the second Concrete block layer 5 up to an imaginary level along the highest elevations 11.

The Figures 3 and 4 show a roughly simplified representation of an exemplary embodiment of the concrete block 1 according to the invention, again in a perspective view and in a vertical section in a section plane parallel to the main axis HA and to the vertical axis VA of the concrete block 1. In contrast to the variant of Figures 1 and 2 the concrete block body 2 of the exemplary concrete block 1 is designed in three layers and additionally has a third concrete block layer 6 designed as a facing concrete layer, which is arranged on the concrete block top 2.2 and in this embodiment the surface that can be walked on or driven over, namely the visible surface or the exposed concrete of the im Surface covering 10 laid concrete block 1 forms. The third concrete block layer 6 with a layer thickness d3 is made from a structurally dense facing concrete, in particular from a structurally dense facing concrete with fine aggregates and / or aggregates for the optical design of the top of the concrete block. In the example shown, the concrete block layers 6, 4, 5 follow one another along the vertical axis VA, with the first concrete block layer 4 being arranged between the second and third concrete block layers 5, 6.

The exemplary concrete block 1 also has spacers 8 or spacer lugs arranged on the peripheral sides 7, 7 ', 7", 7"' and extending at least over the area of the first concrete block layer 4 and in the form of projections, which are used when laying the concrete blocks 1 ensure uniform joints 13 of approximately uniform width in the composite and ensure that the joints 13 have a minimum width. Of course, such spacers 8 or spacer lugs can also be used with one as in Figures 1 and 2 Concrete block 1 shown can be provided with a two-layer concrete block body 2.

The Figure 5 Section A shows a very simplified and only sketchy outline of a section of the underside of the concrete block 2.1 in a top view of the coarse-grained surface 5a. That in section A of the Figure 5 The Cartesian coordinate system shown in simplified form indicates the extension of the coarse-grained surface 5a, which is essentially oriented in the xz direction. Projected onto a laid surface covering 10, the xz direction is essentially to be understood as a plane running parallel to the subsurface or the terrain, which, for example, runs horizontally or is aligned with a slope of the subsurface.

As already mentioned above, the coarse-grained surface 5a has projections 11 and depressions 12, the projections 11 being formed by the rock grains of the coarse aggregate of the coarse, porous concrete of the second concrete block layer 5. The depressions 12 are the pores open to the outside on the surface 5a or the cavities open to the outside, which are present, in particular enclosed, in the coarse, porous concrete layer between the rock grains of the coarse rock grain.

The coarse-grained surface 5a of the underside of the concrete block 2.1 is therefore open-pored, namely with a large number of pores open to the outside, which open outwards via a respective pore opening on the surface 5a of the underside of the concrete block 2.1. The pore openings have different opening widths, which in turn depend on the average grain size of the coarse aggregate. At least some of the pores that are open to the outside have a pore opening that approximately corresponds to the average grain size of the aggregate. In the concrete blocks 1 shown as an example Figures 1 to 4 at least some of the pore openings have an opening width in a range of 2 to 5 mm. Likewise, at least some of the open pores have a pore depth in a range of around 2 to 5 mm. This ensures, for example, that bedding material of the bedding layer 3 can engage in the open pores for interlocking. For example, using grit with a grain size of 2/5 as bedding material ensures efficient interlocking.

The toothing means in the coarse-grained surface 5a, in particular the projections 11 and depressions 12, are arranged distributed over the entire underside of the concrete block 2.1, in particular distributed over the entire surface, although the distribution pattern is disordered or irregular and can also be understood as a random distribution pattern. This full-surface and irregular arrangement of the toothing means over the entire underside of the concrete block 2.1 also results in a flat, in particular full-surface, toothing, which is advantageously particularly stable, firm, effective and effective. In contrast to interlocking that occurs only at points, in an orderly manner or along orderly lines, the full-surface interlocking of the present concrete blocks 1 with the bedding layer 3 provides a greatly improved, increased "adhesion" of the concrete blocks 1 on the bedding layer 3 as well as a better grip against displacements. This increased "adhesion" and the improved hold is additionally supported or reinforced by the fact that the toothing means themselves are supported by the aggregate in the form of broken stones in the second Concrete block layer 5 is formed, and such quarry stone has irregular shapes and rough, angular, "hooking" properties.

The concrete blocks 1 are simultaneously secured against displacements in several, diverse possible displacement directions in the xz plane due to the toothing means distributed over the entire surface and in a disordered or irregular manner, in section B the Figure 5 For the sake of clarity, only a selection of possible displacement directions S1/-1, S2/-2, S3/-3 to Sn/-n is indicated. The present concrete block 1 is therefore not only secured against displacement in the direction of its main axis HA (e.g. displacement direction S1/-1), but at the same time also against displacement in a direction perpendicular to the main axis (e.g. displacement direction S3/-3) and also along one A variety of different displacement directions S2/-2 - Sn/-n that run obliquely to the main axis HA.

In the same way as described here for the coarse-grained surface 5a of the underside of the concrete block 2.1, the coarse-grained side surface sections 7a present in the area of the second concrete block layer 5 are also provided with respective projections and depressions, which are formed by the rock grains or through the pores between the rock grains of the aggregate-porous concrete layer are formed. Even in the case of the coarse-grained side surface sections 7a, interlocking takes place with bedding material of the bedding layer and/or with joint material with which the joints 13 in the surface covering 10 are filled.

Figure 6 shows an example of a surface covering 10 made from several concrete blocks 1 in a vertical section. The concrete blocks 1 are laid together by paving and lie with their respective concrete block undersides 2.1 on the bedding material of the bedding layer 3. Joints 13 are formed between the individual concrete blocks 1 and are filled with a chip-like joint material.

In the example shown, the bedding layer 3 is formed from grit which, for example, has a grain size of 2/5. When the surface covering 10 is created, when the concrete blocks 1 are laid, the projections 11 present on the coarse-grained surface 5a of the undersides of the concrete blocks 2.1 (see Figures 1 and 5 ) interlocking into the bedding layer 3. Likewise, rock grains of the chippings, namely chippings of the bedding layer 3, interlock with the recesses 12 of the coarse-grained surface 5a on the underside of the concrete block 2.1. This can be done, for example, when creating the surface covering 10 by shaking, can be additionally promoted or supported in particular by shaking the chippings into the depressions 12 or open pores of the concrete block 1.

This "double" engagement mechanism, in particular a toothing mechanism, results in an effective interlocking of the second concrete block layer 5 with the bedding layer 3. Since the projections 11 and depressions 12 are arranged distributed over the entire underside of the concrete block 2.1, the interlocking advantageously takes place over the entire surface, in particular over the entire surface. Due to the disordered, irregular distribution pattern of the projections 11 and recesses 12, the toothing is advantageously carried out in such a way that anti-displacement protection in several directions is guaranteed. The concrete blocks 1 are therefore effectively secured against displacement, as described above in connection with Figure 5 explained - against displacements in numerous displacement directions S1/-1 - Sn/-n.

Reference symbol list

1

Concrete block

2

Concrete block body

2.1

Concrete block underside

2.2

Concrete block top

3

Bedding layer

4

first layer of concrete blocks

5

second layer of concrete blocks

5a

coarse-grained surface

6

third layer of concrete blocks

7, 7', 7", 7‴

Perimeter pages

7a

coarse-grained side surface section

8th

Spacers

10

surface covering

11

Projections

12

depressions

13

Put

d1

Layer thickness of the first concrete block layer

d2

Layer thickness of the second concrete block layer

d3

Layer thickness of the third concrete block layer

E

Concrete block boundary level

H

Height of the concrete block

HA

main axis

S1/-1 - Sn/-n

Shift directions

VA

Vertical axis

Claims (14)

1. Concrete block (1) in the form of a paving block that can be laid in bond to create a surface covering, comprising at least one multi-layered concrete block body (2) having at least one concrete block underside (2.1) suitable for laying on a bedding layer (3) of an underground and an opposite concrete block top side (2.2) , wherein the multi-layered concrete block body (2) comprises at least one first concrete block layer (4), which is produced from core concrete material and is designed as a core concrete layer, and at least one second concrete block layer (5), which is arranged on the concrete block underside (2.1), and also at least one third concrete block layer (6), which is designed as a face concrete layer and is arranged on the concrete block top side (2.2), wherein the second concrete block layer (5) is a coarse, no-fines concrete layer and is produced from a concrete with a coarse aggregate, wherein the second concrete block layer (5) is designed as an interlocking layer for interlocking with the bedding layer (3) of the underground, and the concrete block (1) is thereby provided on the concrete block underside (2.1) with a coarse-grained surface (5a) providing a plurality of interlocking means.
2. Concrete block (1) according to claim 1,
   characterised in that
   the coarse aggregate of the concrete of the second concrete block layer (5) comprises a grain size in a range of approximately 5 mm to 15 mm.
3. Concrete block (1) according to claim 1 or 2,
   characterised in that
   the coarse aggregate of the concrete of the second concrete block layer (5) comprises a grain size in a range of approximately 5 mm to 8 mm or in a range of 8 mm to 11 mm, and/or in that the second concrete block layer (5) is produced from a concrete without sand and/or fine aggregate.
4. Concrete block (1) according to one of the preceding claims,
   characterised in that
   the second concrete block layer (5) comprises a layer thickness (d2), wherein the layer thickness (d2) of the second concrete block layer (5) is between approximately 10 % and 50 % of a height (h) of the concrete block (1), in particular around 20 % of the height (h) of the concrete block (1), and/or in that the surface (5a) of the concrete block underside (2.1) is open-pored and comrises a plurality of outwardly open pores, wherein the outwardly open pores have a respective pore opening.
5. Concrete block (1) according to claim 4,
   characterised in that
   at least some of the outwardly open pores in the surface (5a) of the concrete block underside (2.1) have a pore opening with an opening width in a range of 1 mm to 8 mm, in particular in range of 2 to 5 mm, and a pore depth in a range of around 1 mm to 8 mm, in particular in a range of around 2 to 5 mm.
6. Concrete block (1) according to one of the preceding claims,
   characterised in that
   the third concrete block layer (6) is produced from a dense-structured face concrete, in particular from a dense-structured face concrete with fine aggregates and/or aggregates for the optical design of the concrete block top side (2.2).
7. Concrete block (1) according to one of the preceding claims,
   characterised in that
   the concrete block (1) comprises at least three mutually adjoining peripheral sides (7, 7', 7"), wherein the peripheral sides (7, 7', 7") comprise at least partially a coarse-grained side face portion (7a) in the region of the second concrete block layer (5), and/or in that the concrete block (1) comprises one or more laterally arranged spacers (8).
8. Surface covering (10) comprising a plurality of concrete blocks (1) according to one of claims 1 to 7 laid in bond by paving and at least one bedding layer (3) arranged on an underground, wherein each concrete block (1) comprises a multi-layered concrete block body (2) having at least one concrete block underside (2.1) and an opposite concrete block top side (2.2) , and wherein the multi-layered concrete block body (2) comprises at least one first concrete block layer (4), which is produced from core concrete material and is designed as a core concrete layer, and at least one second concrete block layer (5), which is arranged on the concrete block underside (2.1), and also at least one third concrete block layer (6), which is designed as a face concrete layer and is arranged on the concrete block top side (2.2), wherein the second concrete block layer (5) of the concrete blocks (1) is a coarse, no-fines concrete layer and is produced from a concrete with a coarse aggregate, wherein the concrete blocks (1) comprise on their concrete block underside (2.1) a coarse-grained surface (5a) providing a plurality of interlocking means, due to the second concrete block layer (5) being designed as an interlocking layer for interlocking with the bed layer (3) of the substrate, and wherein the concrete blocks (1) are interlocked with the bedding layer (3) via their respective second concrete block layer (5) and are thereby secured against displacement.
9. Surface covering (10) according to claim 8,
   characterised in that
   the bedding layer (3) comprises a bedding material in the form of a gravel material, wherein the gravel material of the bedding layer (3) interacts with the coarse-grained surface (5a) to interlock with the second concrete block layer (5) and/or at least partially engages in outwardly open pores of the second concrete block layer (5).
10. Surface covering (10) according to claim 8 or 9,
    characterised in that
    joints (13) are formed between respective adjacent concrete blocks (1) of the surface covering (10), wherein the joints (13) are filled with a gravel- and/or sand-like joint material.
11. Surface covering (10) according to claim 10,
    characterised in that
    the concrete blocks (1) each have at least one coarse-grained side face portion (7a) on their peripheral sides (7, 7', 7") in the region of the second concrete block layer (5), wherein the coarse-grained side face portions (7a) of the concrete blocks (1) interact interlockingly with the joint material.
12. Method for producing a concrete block according to one of claims 1 to 7, in which, after providing a suitable formwork mould, a face concrete material is first poured into the formwork mould and preferably compacted to produce a third concrete block layer (6) designed as a face concrete layer, in which a core concrete material is then poured into the formwork mould and preferably compacted to produce a first concrete block layer (4) designed as a core concrete layer, and in which in a further step a second concrete block layer (5) is produced, which defines a concrete block underside (2.1) of the produced concrete block, wherein the second concrete layer (5) is produced as a coarse, no-fines concrete layer, and the concrete block (1) is thereby provided on its concrete block underside (2.1) with a coarse-grained surface (5a) providing a plurality of interlocking means, wherein to this end a concrete with a coarse aggregate is provided and added to the face and core concrete material already introduced into the formwork mould and preferably compacted, respectively, and in which finally the face and core concrete material and the concrete with coarse aggregate is set.
13. Method according to claim 12,
    characterised in that
    for producing the second concrete block layer (5), a concrete is used which comprises a coarse aggregate with a grain size in a range of approximately 5 mm to 15 mm, in particular with a grain size in a range of approximately 5 mm to 8 mm or in a range of 8 mm to 11 mm, and/or in that for producing the second concrete block layer (5), a concrete is used which is free of sand and/or fine aggregates.
14. Method according to one of claims 12 or 13,
    characterised in that
    for producing the second concrete block layer (5), a sufficient amount of concrete is introduced to produce the second concrete block layer (5) with a layer thickness (d2) which is between approximately 10 % and 50 % of a height (h) of the concrete block (1), in particular around 20 % of the height (h) of the concrete block (1).

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